/*
 * Copyright (c) 2016, 2017 ARM Limited.
 *
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

layout(local_size_x = LOCAL_SIZE_X, local_size_y = LOCAL_SIZE_Y, local_size_z = LOCAL_SIZE_Z) in;

#include "helpers_cs.h"

/** Performs an affine transformation on an image interpolating with the NEAREAST NEIGHBOUR method. Input and output are single channel FP16.
 *
 * @param[in]  src_ptr      Pointer to the source tensor. Supported data types: FP16.
 * @param[in]  src_attrs    The attributes of the source tensor
 * @param[out] dst_ptr      Pointer to the destination tensor. Supported data types: FP16. (Must be the same as the input)
 * @param[in]  dst_attrs    The attributes of the destination tensor
 * @param[in]  input_width  Input image width
 * @param[in]  input_height Input image height
 * @param[in]  scale_x      The scale factor along x dimension
 * @param[in]  scale_y      The scale factor along y dimension
 */
SHADER_PARAMS_DECLARATION
{
    ImageAttributes src_attrs;
    ImageAttributes dst_attrs;
    float           input_width;
    float           input_height;
    float           scale_x;
    float           scale_y;
};

#if defined(DATA_TYPE_FP16)
#if defined(SCALE_NEAREST_GENERIC)
TENSOR_DECLARATION(1, srcBuffer, uint, src_ptr, src_shift, 2, readonly);
TENSOR_DECLARATION(2, dstBuffer, uvec2, dst_ptr, dst_shift, 3, writeonly);

vec4[2] transform_nearest(vec2 coord, vec2 scale)
{
    vec4 in_x_coords = vec4(coord.x, 1.f + coord.x, 2.f + coord.x, 3.f + coord.x);

    vec4[2] t;
    t[0] = (in_x_coords + (vec4(0.5f))) * scale.x;
    t[1] = vec4((coord.y + 0.5f) * scale.y);

    return t;
}

vec4[2] clamp_to_border_with_size(vec4[2] coords, float width, float height, float border_size)
{
    vec4[2] c;
    c[0] = clamp(coords[0], 0.0f - border_size, width - 1.f + border_size);
    c[1] = clamp(coords[1], 0.0f - border_size, height - 1.f + border_size);

    return c;
}

void main()
{
    ImageIterator src_iter = CONVERT_TO_IMAGE_ITERATOR_NO_STEP(src_attrs, src_shift);
    ImageIterator dst_iter = CONVERT_TO_IMAGE_ITERATOR(dst_attrs, dst_shift);

    vec2 r     = vec2(scale_x, scale_y);
    vec4[2] tc = clamp_to_border_with_size(transform_nearest(vec2(gl_GlobalInvocationID.x << uint(2), gl_GlobalInvocationID.y), r), input_width, input_height, float(BORDER_SIZE));

    mediump vec2 s = vec2(0.0f);
    mediump vec4 d = vec4(0.0f);

    for(int i = 0; i < 4; i++)
    {
        uint offset = image_offset_in_bytes(src_iter, int(tc[0][i]), int(tc[1][i]));

        s = LOAD_UNPACK2_HALF(src_ptr, uint(offset >> src_shift));

        if(offset % uint(4) == uint(0))
        {
            d[i] = s.x;
        }
        else
        {
            d[i] = s.y;
        }
    }

    STORE_PACK4_CURRENT_ITEM_HALF(dst_ptr, dst_iter, d);
}
#elif defined(SCALE_NEAREST_8X) /* SCALE_NEAREST_GENERIC */
TENSOR_DECLARATION(1, srcBuffer, uvec2, src_ptr, src_shift, 3, readonly);
TENSOR_DECLARATION(2, dstBuffer, uvec4, dst_ptr, dst_shift, 4, writeonly);

void main()
{
    ImageIterator src_iter = CONVERT_TO_IMAGE_ITERATOR_NO_STEP(src_attrs, src_shift);
    ImageIterator dst_iter = CONVERT_TO_IMAGE_ITERATOR(dst_attrs, dst_shift);

    uvec2 tc = uvec2(gl_GlobalInvocationID.x << uint(2), gl_GlobalInvocationID.y >> uint(1));

    mediump vec4 s = vec4(0.0f);
    mediump      vec4[2] d;

    uint offset = image_offset_in_bytes(src_iter, int(tc[0]), int(tc[1]));
    s           = LOAD_UNPACK4_HALF(src_ptr, uint(offset >> src_shift));

    d[0] = vec4(s.x, s.x, s.y, s.y);
    d[1] = vec4(s.z, s.z, s.w, s.w);

    STORE_PACK8_CURRENT_ITEM_HALF(dst_ptr, dst_iter, d);
}
#endif                          /* SCALE_NEAREST_GENERIC */

#else /* DATA_TYPE_FP16 */
#error Data type not supported
#endif /* DATA_TYPE_FP16 */